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Does anyone think its worth it to invest in a beam antenna to extend the range of 2 meter simplex.The reason I ask is there's a group wanting to start a simplex group for emergency relay communications on 2 meters.So far I haven't been able to contact anyone in the area of the core group yet.
Sure it is. Nice thing about 2m is that you can build yourself a beam antenna quite easily. I made one out of #14 AWG bare copper ground wire and a wooden dowel—worked great, although it was a little fragile. Note use of the past tense there. If I had to do it over again, I'd use 1/4" CU tubing.
What's the current 2m antenna, how high is it, and will the beam be at the same height as the current antenna?
I can think of a couple of plausible layouts involving fixed-pointed 5-7 element Yagis or quads and some method of switching between them. One pointed in each of the "major" directions you wish to cover, and gain/beamwidth factoring into the design calculations.
Are you in the center of the activity or is everyone in the group you're trying to reach clustered in one discrete area?
Lots of simplex activity in my area, so it'd be worth it. However, I'd focus more on getting your antenna higher. With 2 meters, height is king, directionality is queen.Quote:
Originally Posted by kk4fpx
I'm on a j-pole at the present.It's only 17 feet to the bottom of it.I can get it about 3 of 4 feet higher or if I don't get a beam I can put it on top of the tower which would put it at about 28 feet.
Also I'm probally 50 miles from the main group.I'm on a mountian but in a hollow.
If the mountain is between you and the group, it's going to be tough to work them, no matter what the antenna is.
Antenna height is going to more important than anything.
It depends on the direction of the nearest club member as to if I'm blocked or not.
Build the beam. It can only help.
This is the first 2M Beam I built. I used parts scabbed from a TV antenna. AT 40 feet I could work stations 75 Miles away simplex. KA9NRT stacked 2 of them. That thing was awesome.
Attachment 6421Attachment 6422
I made one of those "tape measure Yagi" beams, and it worked surprisingly well. Wonderful for direction finding/foxhunting stuff because the elements will self correct if you're being careless and clumsy.
Be sure to honor the preferred polarization of the group (vert/horizontal). It would be a shame to make that investment in antenna just to take a big db loss from not thinking about the proper way to implement it.
I would generally agree to "make the beam, it'll only help"; but seeing as you're in a hollow, I'm not sure how much it would help when trying to hit those that have a mountain between you and them. Maybe with some fancy aiming, taking advantage of the fresnel effect, maybe. It'll definitely help hitting those with clear space between you and them, however.
Definitely !!Quote:
Originally Posted by kk4fpx
I've kind of thought about going to a pair of beams for 2m/440 myself...weighing some options for when I upgrade the antennas later this year. 90% of the repeaters I'd want to reach are within the beamwidth of a fixed 3 element Yagi, but I'd hate to get some up and realize it's the lack of height that I'm hearing :(
Yes, height is king. You didn't suggest the size of the mountain you'd need to fire through but nil desperandum I can work through an 800ft hill OK to maintain contact 35 miles away with just 2.5W into a Hentenna with reflector. Let's say equivalent to a 3-element Yagi or Quad.
Talking about height,i had to lower my jpole 2 meter to be able to hear two of my triends accross the hill.